This invention relates to record storage apparatus comprising a stack of coaxially arranged flexible record storage disks, and relates more particularly to apparatus and methods for accessing a record surface on a selectable one of the disks in the stack in a manner that enables said record surface to be resiliently fluid pressure loaded into operative contact with the transducer.
The above-identified related patent applications disclose and claim apparatus and methods for generating access to a record surface in a stack of rotating flexible disks by applying a jet of pressure fluid in a generally radial direction to separate a selectable disk from its immediately adjacent disk, thereby to create a gap into which a transducer is insertable for operative contact with the record surface of the selected disk. The jet of pressure fluid may be applied by an air jet knife that is movable in a radial direction radially inwardly and outwardly from adjacent the periphery of the pack. Alternatively, the jet of pressure fluid may be applied via at least one port in the periphery of a member that is slidably positioned in alignment with the point at which the pack is to be split, pressure fluid being supplied to such port via a hollow control rod and internal opening in the member. This member is sealingly slidable in a bore within the disk pack so as to isolate the interstices between the disks at one side of said port from the port and from the interstices between the disks at the opposite side of said port. In most of the related applications, pressure fluid at an identical preselected flow rate was supplied to both sides of the member to normally maintain all disks of the pack in stablized substantially parallel relation until the pack was split by the jet of pressure fluid, assisted in the case of reference (4) above by preapplication of a vacuum between a pair of axially spaced jet ports.
Although the apparatus and methods disclosed in these related applications were generally satisfactory, there is a need for a somewhat less complex apparatus and method for facilitating access of a transducer to a record surface of a selected disk, while at the same time desirably providing for a resilient fluid pressure loading of the record surface operatively against the transducer and also creating a stable (i.e., smoother) recording platform.